The invention relates to a sampling system for stool analysis and method of use thereof.
For many diagnostic tests, it is important to obtain truly representative stool samples to ensure meaningful results. Diagnostic tests include chemical, parasitic and microbiological tests. Known tests permit detection and/or measurement of fecal occult blood; fats; bile and bile salts; porphyrines; parasitic agents; microbiological agents (bacteria etc); and drug and drug metabolites, for diagnostic and various other purposes.
Although the bases of most known analyses systems are sound, the sensitivity and reliability of these tests are dependent on proper specimen sampling. In most cases, specimen sampling is accomplished by the patient after the specimen has been deposited in a toilet. For example, the specimen can be scraped with a five inch wooden applicator, and smeared onto specially prepared chemically impregnated paper (slide) for use in fecal occult blood analysis. Even if the entire stool specimen is collected, sampling must still be done by a laboratory technician. Typically, the sample on the slide is covered with a paper flap which closes over the specimen, and the slide is sent through the mail or hand delivered to a laboratory or doctor's office for testing with guaiac or orthotolidine reagents for colorimetric hemoglobin determination. Many patients find this--and in fact all--stool sampling techniques requiring handling repugnant.
Prior sampling procedures have a number of disadvantages which are inherent therein. A primary disadvantage is that the sample collected is not necessarily representative of the entire specimen. Without a representative sample, the agent being detected may not appear or may appear at a non-representative concentration. For example, no blood may be detected by a fecal occult blood test even though it is present in the stool. A scraping sampling method requires that the blood or other agent in the stool be primarily on the surface of the specimen. However, if the agent is mixed into the feces far enough up in the digestive canal, it can be buried in the sample and not be available for sampling.
Other disadvantages include the question of hygiene for both the handlers of the sample and of the mail through which the sample is often sent to the laboratory for testing. Furthermore, the sampling method and the transmission to the laboratory through the mail on a slide, can result in damage to the sample itself if not properly protected. The sample can dry out or be degraded by atmospheric contaminants, especially humidity.
There is also the question of patient compliance in regard to collecting an appropriate specimen. As noted above, many patients find the collection instructions and procedure repugnant and will either not collect the specimen or incorrectly collect the specimen in any way they can get it over with. Poor patient compliance, i.e. improper sampling, obviates the clinical utility of various tests.